KR20190131370A - gas treatment system and offshore plant having the same - Google Patents

Abstract

The present invention relates to a gas treatment system and a marine structure having the same. The gas treatment system, which is provided on a marine structure adjacent to the coast, is supplied with gas from the land, and processes the same, includes: a preprocessing unit removing impurities from the gas to dry the same; an NGL processing unit separating NGL from the gas from which the impurities are removed; a liquefying unit liquefying the gas from which the NGL is separated; a condensate processing unit processing condensate contained in the gas; a slop processing unit processing a slop contained in the gas; and a fuel supply unit supplying the gas to a demand source, wherein the condensate processing unit stores the separated condensate without additional separation after separating the impurities separated in the preprocessing unit into the slop and the condensate by using a density difference.

Description

Gas treatment system and offshore plant having the same

The present invention relates to a gas treatment system and an offshore structure comprising the same.

As environmental regulations have recently been tightened, the use of natural gas, which is close to an environmentally friendly fuel, is increasing among various fuels. Natural gas can be extracted in gaseous form from wells located in the inland or ocean strata. The extracted natural gas undergoes pretreatment such as mercury removal, drying, or NGL removal, followed by liquefaction for storage and transportation. Can be liquefied through.

Natural gas can be cooled to below the boiling point (for example, -162 ℃ under 1 atm) while being exchanged with a refrigerant, and can be converted into a liquid state. Transport efficiency can be increased.

The liquefaction process as described above may be performed in a land plant or FLNG on the sea, and liquefied natural gas may be stored in an LNG storage tank and then supplied to a consumer.

For example, natural gas may be supplied from LNG storage tanks to onshore city gas facilities or power generation facilities, or may be delivered to cargo tanks of LNG carriers and transported to desired areas by LNG carriers.

At this time, the natural gas may be consumed by being vaporized after being discharged from the LNG storage tank or cargo tank, the vaporization facility may be provided in a land plant or FLNG, or in a facility that consumes natural gas.

As such, natural gas is extracted from gas wells and consumed through pre-treatment, liquefaction, storage, transportation, and gasification processes in turn. Various research and development is conducted to ensure stability and improve efficiency of gas production, treatment, and supply. This is constantly being done.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention, to provide a gas treatment system and an offshore structure including the same to enable the efficient treatment of natural gas in the coast adjacent to the land. It is for.

According to an aspect of the present invention, there is provided a gas treatment system, which is provided in a marine structure adjacent to a coast and receives and processes gas from a land, comprising: a pretreatment unit for removing impurities from a gas and drying the gas; An NGL processor separating the NGL from the gas from which impurities are removed; A liquefaction unit for liquefying the gas from which the NGL is separated; Condensate processing unit for processing the condensate contained in the gas; A slop processing unit for processing the slops contained in the gas; And a fuel supply unit supplying a gas to a demand destination, wherein the condensate processing unit separates impurities separated from the pretreatment unit into the slab and the condensate using a density difference and stores the separated condensate without further separation. It is characterized by.

Specifically, the condensate treatment unit, the surge vessel for separating the impurities into the slab and condensate using a partition wall; And it may include a condensate tank for storing the condensate separated from the surge vessel.

Specifically, the surge vessel, one side into which the impurities are introduced based on the partition wall is connected to the slab processing unit, the other side is connected to the condensate tank, and a large density slab is transferred to the slab processing unit and has a high density. The small condensate that has crossed the partition can be delivered to the condensate tank.

Specifically, the surge vessel may maintain the interface between the slab and the condensate lower than the partition wall by adjusting the delivery amount of the slab and the condensate so that the slab does not cross the partition wall.

Specifically, the surge vessel, in addition to the impurities on one side of the partition walls, impurities from the land or the liquefaction portion may be introduced, and the internal pressure may be lowered to evaporate hydrocarbons from the impurities.

Specifically, the surge vessel may return the hydrocarbon evaporated from the impurities to the pretreatment unit.

Specifically, the pretreatment unit, a mercury remover for removing mercury from the gas; Prewash to wash away impurities; An amine contactor for removing an acidic substance by contacting a gas with an amine; And a drier for drying the gas from which the acidic substance has been removed, wherein the surge vessel may return the evaporation gas upstream of the mercury remover.

An offshore structure according to an aspect of the present invention is characterized by having the gas treatment system.

Gas treatment system and offshore structure including the same according to the present invention, by simplifying and standardizing the system by processing natural gas offshore, it is possible to maximize the efficiency of manufacturing / design.

1 is a side view of an offshore structure having a gas treatment system according to the present invention.
2 is a front sectional view of an offshore structure with a gas treatment system according to the present invention.
3 is a state diagram of use of an offshore structure having a gas treatment system according to the present invention.
4 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
5 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
6 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
7 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
8 is a partial conceptual view of a gas treatment system according to an embodiment of the present invention.
9 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
10 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
11 is a partial conceptual diagram of a gas treatment system according to an embodiment of the present invention.
12 is a partial conceptual diagram of a gas treatment system according to another embodiment of the present invention.
13 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.
14 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.
15 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.
16 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.
17 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.
18 is a partial conceptual diagram of a gas treatment system according to another embodiment of the present invention.
19 is a partial conceptual view of a gas treatment system according to another embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings. In the present specification, in adding reference numerals to the components of each drawing, it should be noted that the same components as possible, even if displayed on different drawings have the same number as possible. In addition, in describing the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the gas may mean a material having a boiling point lower than room temperature as hydrocarbons such as LPG, LNG, and ethane, but for convenience, the present invention will be limited to the final production and storage of LNG (methane). In the present specification, the gas is not limited to the gas phase despite the term expression.

Hereinafter, high pressure (HP), low pressure (LP), high temperature, and low temperature are relative and do not represent an absolute value.

1 is a side view of an offshore structure with a gas treatment system according to the present invention, FIG. 2 is a front sectional view of an offshore structure with a gas treatment system according to the present invention, and FIG. 3 is a marine with a gas treatment system according to the present invention. This is a state diagram of the use of the structure.

1 to 3, the offshore structure OP according to the present invention is a facility for receiving, processing, refining, liquefying, storing, and supplying gas produced from a gas well located on land or in the ocean, and supplying it to a demand destination. It may mean an offshore plant such as FSRU.

Of course, the marine structure (OP) of the present invention can be used as a concept encompassing general merchant ships if the gas treatment configuration can be mounted.

The offshore structure OP includes a hull hull side (HS) and a top side (TS) provided on the hull. The hullside HS may be mainly provided with a storage space, for example, a liquefied gas storage tank GT, an oil tank OT, a condensate tank CT, a drain drum DD, and a dirty slop tank DS. And a clean slop tank CS.

Liquefied gas storage tank (GT) is a configuration in which the production gas is purified, liquefied and stored, and may be provided as a membrane type to stably store the gas in a cryogenic liquid state, but is not limited thereto.

The liquefied gas storage tank GT may be provided in plural in the longitudinal direction of the hull, and two or more may be provided in the lateral direction of the hull. The number or arrangement of the liquefied gas storage tank GT may be determined in various ways according to the size of the production gas to be treated by the offshore structure OP.

The oil tank OT stores oil. In this case, the oil may be an oil used as lubricating oil, or an oil used for heat supply in a gas treatment process.

As will be described in detail below, the oil stored in the oil tank OT may be heated by exhaust generated from a demand source such as an engine provided inside the hull, and then supplied to a heat use place that requires heat in the gas treatment process.

The condensate tank CT stores the condensate separated in the gas treatment process. The condensate may be C ₅ or more heavy hydrocarbons contained in the gas produced in the gas well.

 Condensate can be stored in a condensate tank (CT) and then unloaded to land and processed. Condensate is a kind of impurity that is separated during gas purification, but is stored in a condensate tank (CT). It can be sold and consumed.

The drain drum DD stores waste generated in the gas purification process. The waste stored in the drain drum DD, unlike impurities such as condensate, which is a material having a calorie value, corresponds to waste, and may be a material that is difficult to sell or recycle.

Therefore, the waste stored in the drain drum DD may be combusted through the flare tower FT, which will be described later, or may be delivered to land and disposed of. In the present specification, the impurity is a material that can be sold or reused, whereas the waste may mean a material that is discarded by simply storing and delivering to the land, unlike impurities, but the impurity separated in the gas purification process may include waste. For convenience, it is only to distinguish between impurities and waste, but it is important to note that the two substances are completely different and the scope of rights is not limited.

The dirty slop tank DS separates the condensate from impurities separated during the gas treatment and stores the slop, which is the remaining sewage. At this time, the dirty slop tank (DS) may also store the sewage delivered from the hull side (HS).

The dirty slop tank DS is a tank for storing the slops, which occupy most of the water and the relatively dirty sewage, and the slops stored in the dirty slop tank DS are purified through the water processor 54 and transferred to the clean slop tank CS. Can be.

The clean slop tank CS is separated from the top side TS or the hull side HS, stored in the dirty slop tank DS, and then stored in the purified slab by the water processor 54. The clean slop tank (CS) can store refined slop to a level that can be discharged to the outside of the sea, etc., and can discharge the slop to the sea if necessary.

The hullside (HS) may be provided with an engine or a boiler in addition to the storage space, the marine structure (OP) of the present invention may not have a self-propelled function, the engine may be a power generation engine.

In this case, the engine may be driven using gas, and components that consume energy such as engines, boilers, and the like to produce energy (power, power, steam, etc.) may all be referred to / included in the present specification.

The hullside (HS) may be moored offshore or offshore to receive and process production gas. For example, the marine structure OP of the present invention may be moored adjacent to offshore. In this case, the marine structure OP may be moored through land or jetty provided on the coast, but may be provided in a state capable of evacuation according to weather conditions.

The top side TS includes the structure which processes a gas. The top side TS may include a gas processing system 1 to be described later, and the detailed configuration of the gas processing system 1 will be described in detail below.

In the case of the oil tank OT having a relatively small capacity, it is also possible to be provided on the top side TS instead of the hull side HS. In the present invention, the amount of impurities is increased by receiving and processing the gas supplied from the land. Since there are not many, the condensate tank CT, the slop tanks DS and CS, the drain drum DD, etc. can also be arrange | positioned at the top side TS.

In addition to the topside TS, a cabin (not shown), an engine casing (not shown), and a flare tower (FT), which discharge exhaust of the engine, may be further provided on the upper side of the hullside HS. However, most of the upper side of the hullside HS may be utilized for the installation of the topside TS.

The offshore structure OP of the present invention moored offshore is connected to the land facility GP, and can receive and process gas produced on the land from the land. In other words, the offshore structure OP of the present invention is a gas well that is first processed in a land facility GP after being produced in a gas well, and is processed in contrast to a case of receiving and processing a production gas from a deep sea. At this time, the amount of impurities such as condensate or waste contained in the gas may be small.

In addition, since the offshore structure OP of the present invention performs gas treatment in a state moored offshore, it is possible to utilize the land equipment GP, thereby minimizing the treatment configuration such as removal of impurities.

In addition, since the offshore structure OP of the present invention receives and processes the gas treated primarily on land, the gas treatment is different from that of the deep sea offshore structure OP, which had to provide various gas treatment configurations with different characteristics for each gas well. Standardization of the configuration is possible.

That is, the present invention is a coastal offshore structure (OP) (Nearshore FLNG) for receiving and treating primary treated gas on land, and different characteristics of each gas well can be relaxed / resolved by the land facility GP. Through, it has the feature that standardization is possible.

Therefore, the present invention can implement the commercialization through the standardization of the offshore structure (OP) to go beyond the custom-made method that was taken for granted in the shipbuilding / offshore field.

Hereinafter, the gas treatment system 1 of the present invention will be described in detail with reference to FIG. 4 and the like.

4 through 11 are partial conceptual views of a gas treatment system according to an embodiment of the present invention.

4 to 11, the gas processing system 1 according to the exemplary embodiment of the present invention includes a pretreatment unit 10, an NGL processing unit 20, a liquefaction unit 30, a condensate processing unit 40, The slab processing part 50, the heat recovery part 60, the fuel supply part 70, the flare part 80, etc. are included. Of course, the present embodiment can further add various known configurations if necessary for the treatment of the gas.

The pretreatment unit 10 removes impurities from the gas and dries. The pretreatment unit 10 may receive gas from the land, and the gas supplied from the land may be high pressure when compared with the gas supplied from the gas well in the deep sea. For example, the pretreatment unit 10 may receive and process gas at a high pressure of 50 to 80 bar from the land.

The pretreatment unit 10 may remove mercury from the gas, wash off impurities using water, and remove acidic substances using amines. Naturally, both mercury and acid can be interpreted as a kind of impurities.

The pretreatment unit 10 includes a heater 11, a gas-liquid separator 12, a mercury remover 13, a prewasher 14, an amine contactor 15, a knockout drum 16, and a dryer for the pretreatment. 17), the above components may be provided in series on a gas pretreatment line (L10) connected to the land.

The heater 11 heats the gas supplied from the land. The heater 11 can prevent the hydrocarbons from evaporating and mixing with the impurities by heating the gas. In this case, the heater 11 may use various heat sources that are not limited, and oil, electric power, sea water, fresh water, clean slop, and the like may be used.

The gas-liquid separator 12 gas-separates the heated gas. The gas-liquid separator 12 may allow only gas in a gaseous state to be delivered downstream, and may implement a damper role for gas supplied at high pressure from the land.

The gas-liquid separator 12 may return a gaseous hydrocarbon separated by evaporation from the surge vessel 42 of the condensate processing unit 40 to be described later, which will be described later.

The mercury remover 13 removes mercury from the gas. Since mercury may be included in the gas produced in the gas well, the mercury remover 13 may remove mercury from the gas through a known method. Of course, since the present invention is a marine offshore structure (OP) to receive and process the gas supplied from the land, the gas from which mercury is removed from the land can be supplied to the pretreatment unit 10, the mercury remover 13 can be omitted. .

The prewashing period 14 can wash out impurities using water or the like. As described above, the impurities may include condensate, slop, and the like, and the condensate may be separated from the impurities in the condensate processing unit 40.

The amine contactor 15 removes acidic substances by bringing a gas into contact with an amine. Amine can separate various harmful acidic substances from gas through chemical reaction and can be reused through separate treatment.

The amine may be heated and reused through a low temperature oil heated in the heat recovery unit 60 to be described later, and the detailed description of the amine may be omitted since a known method may be used.

The knock-out drum 16 may separate the liquid phase from the gas from which the acidic substance has been removed. The knockout drum 16 may temporarily store gas and deliver the gas to the dryer 17. The liquid phase separated from the knockout drum 16 may be a condensate treatment unit 40 together with impurities separated from the prewasher 14 as impurities. Can be delivered.

The dryer 17 dries the gas from which the acidic substance was removed using the heat source. The dryer 17 may remove moisture contained in the gas, and the heat source may be heated through the hot oil heated in the heat recovery unit 60.

To this end, the heat source supply unit 18 may be connected to the dryer 17, and the heat source supply unit 18 may heat the heat source using the hot oil heated by the exhaust and supply the heat source to the dryer 17. Therefore, the dryer 17 can dry a gas using the heat source indirectly heated from the exhaust of a consumer.

The NGL processing unit 20 separates NGL from the gas from which impurities are removed. NGL (Natural Gas Liquids) is a natural gas liquid, the main component may be butane, pentane and the like.

NGL is a material that can be used as fuel because it has a calorific value, but the present invention is different from the gas (for example, LNG) to be finally produced, and thus can be separated and treated separately.

At this time, the separated NGL may be burned by the flare tower (FT) or stored separately to be used as a refrigerant. In the present embodiment, the NGL processing unit 20 may separate LPG and ethane, the main component of butane.

To this end, the NGL processing unit 20 includes a gas-liquid separator 21, an expander (extender) 22, a compressor 23, a precooler 24, a stabilizer 25, first to third columns 25c, and a drum ( 26).

The gas-liquid separator 21 separates gas from which impurities are removed in the pretreatment unit 10 into gas-liquid separation. At this time, the gas of the gas is regarded as the separated NGL is delivered to the liquefaction unit 30 through the NGL separation gas delivery line (L20), the expander 22, compressor 23, free to the NGL separation gas delivery line (L20) The cooler 24 may be provided.

On the other hand, the gas of the liquid separated from the gas-liquid separator 21 is considered to mainly contain NGL, and may be transferred to the stabilizer 25 through the NGL separation line L21. That is, the gas-liquid separator 21 may be configured to primarily separate NGL.

The expander 22 lowers the pressure of the gaseous gas separated by the gas-liquid separator 21 to lower the temperature to cool the gas to separate the NGL.

The compressor 23 compresses the gas expanded in the expander 22. At this time, the compressor 23 may compress the gas at a suitable pressure in the liquefaction section 30 (which may be the same / similar pressure as that of the refrigerant used in the liquefaction section 30), and the gas may have a boiling point by compression. As it rises, the rate of liquefaction can be high during compression.

The compressor 23 may be connected to the same axis as the expander 22, in which case the expander 22 and the compressor 23 may constitute the compander 31. However, the present embodiment lowers the pressure of the gas and then raises it again, in the NGL separation gas delivery line L20, the first column 25a provided between the expander 22 and the compressor 23 separates the NGL using the boiling point difference. To do that.

The precooler 24 precools the gas compressed by the compressor 23. The gas precooled by the precooler 24 may be liquefied by exchanging heat with the refrigerant in the liquefaction unit 30, and the precooler 24 may precool the gas by using ethane, which will be described later, as a refrigerant.

The stabilizer 25 separates NGL from the gas in the liquid state separated from the gas-liquid separator 21. The stabilizer 25 may implement separation of NGLs by utilizing differences in boiling points of components included in the gas, but is not limited thereto.

The gaseous gas separated in the stabilizer 25 is transferred to the first column 25a between the expander 22 and the compressor 23, and the gas in liquid or liquid / gas mixed state separated in the stabilizer 25. Is delivered to the second column 25b, and the liquid gas separated from the stabilizer 25 may be delivered to the third column 25c. In addition, the gas in the liquid state separated in the first column 25a and the second column 25b may be returned to the stabilizer 25.

The first column 25a is located between the expander 22 and the compressor 23 and separates the NGL from the gas that has passed through the expander 22 or stabilizer 25. The gaseous gas separated in the first column 25a may be delivered to the compressor 23 as NGL is removed, and the gaseous liquid separated in the first column 25a may contain NGL as a stabilizer. 25).

The second column 25b receives gas from the stabilizer 25, passes the gas in the gas state to the first column 25a, the gas in the liquid state to the stabilizer 25, and separates ethane from the gas. have.

The ethane separated by the second column 25b may be stored in an ethane tank (not shown) through the ethane collection line L22, and the precooler 24, the liquefaction unit 30, and the intercooler 47. It can be utilized as a refrigerant of.

The third column 25c receives the liquid gas separated from the stabilizer 25, and the gas gas is delivered to the drum 26 as a main component of butane and the like, similar to LPG. The gas is delivered to the condensate tank CT as condensate.

The drum 26 stores butane and the like separated from the gas delivered from the pretreatment unit 10 via the gas-liquid separator 21, the stabilizer 25, and the third column 25c. That is, the drum 26 may be configured to store the LPG separated from the gas, in which the stored LPG may be used as fuel at the demand or burned in the flare tower FT through the flare line L23.

The liquefaction unit 30 liquefies the gas from which NGL was isolate | separated. The liquefaction unit 30 cools gas by using a refrigerant, and includes a compander 31, a gas-liquid separator 32, a liquefier 33, a refrigerant supply 34, a pressure reducer 35, and a flash drum 36. It includes.

At this time, the NGL separation gas delivery line L20 of the NGL processing unit 20 is connected to the gas liquefaction line L30 of the liquefaction unit 30, and the liquefier 33 and the compander 31 are connected to the gas liquefaction line L30. And a gas-liquid separator 32, a pressure reducer 35, and a flash drum 36 are provided.

The compander 31 expands and compresses a gas. The liquefier 33 may cool the gas at least two or more stages by using a refrigerant. For example, the liquefier 33 implements precooling and main cooling, and the compander 31 is a liquefier 33 between the precooling and the main cooling. The gas discharged from it may be expanded and compressed to return to the main cooling of the liquefier 33.

The compander 31 may have a form in which the expansion part 31a and the compression part 31b are connected by one axis, and a gas-liquid separator is provided between the expansion part 31a and the compression part 31b of the compander 31. 32 may be provided.

The gas-liquid separator 32 receives gas expanded by the compander 31 and separates the gas-liquid. At this time, the liquid gas separated from the gas-liquid separator 32 may be delivered to the condensate processing unit 40.

In the case of precooling, the gas is cooled by using a refrigerant that has already exchanged heat with gas in the main cooling, and thus it is not sufficient to liquefy light hydrocarbons such as methane. Thus, the gas cooled in the precooling and liquefied by expanding in the expansion part 31a may be heavy hydrocarbons, which may be treated with condensation.

The liquefier 33 cools the gas using a refrigerant, and the refrigerant used in the liquefier 33 may be nitrogen, hydrocarbons such as propane, or mixed refrigerants.

The liquefier 33 may be provided in a structure having a stream in which gas flows and a stream in which a refrigerant flows, and when the refrigerant is a mixed refrigerant or the like, two or more streams of refrigerant may be provided.

The stream of gas provided in the liquefier 33 may be divided into precooling, main cooling, and subcooling. Precooling primarily cools the gas introduced into the liquefier 33 with a refrigerant, in which light hydrocarbons are not liquefied and only heavy hydrocarbons are liquefied or cooled close to the boiling point. Therefore, the heavy hydrocarbon may be liquefied by the expansion part 31a of the compander 31 and then transferred to the condensate treatment part 40 through the gas-liquid separator 32.

The main cooling is to liquefy the gas introduced through the compander 31 to the refrigerant. Since the gas is compressed by the compander 31 and the boiling point rises, light hydrocarbons such as methane contained in the gas are liquefied in the main cooling. Can be.

Sub-cooling may be provided to increase the liquefaction rate of the liquefier 33, and implements heat exchange with the refrigerant to sufficiently liquefy the gas that has not been liquefied in the main cooling. Unlike the subcooling and the precooling or the main cooling, a 1: 1 stream heat exchange between the refrigerant and the gas may be performed.

The coolant supplier 34 supplies a coolant to the liquefier 33, and may compress / cool / expand / gas-separate the coolant. The refrigerant supplier 34 may control the refrigerant to be suitable for precooling, main cooling, and subcooling of the liquefier 33, and a detailed configuration such as compressing the refrigerant may vary depending on the type of refrigerant.

The pressure reducer 35 decompresses the gas discharged from the liquefier 33. The pressure reducer 35 may be a Joule-Thompson valve, and the temperature of the gas may be lowered by the Joule-Thomson effect while the gas is decompressed by the pressure reducer 35. Therefore, the pressure reducer 35 can further cool the gas cooled by the liquefier 33 by depressurizing, and further increase the liquefaction rate of the gas.

The flash drum 36 separates the flash gas from the gas reduced in the pressure reducer 35. The gas is liquefied through the liquefier 33 and the pressure reducer 35, but some gaseous gas (hereinafter referred to as flash gas) may remain.

At this time, the flash drum 36 may separate the flash gas and transfer the gas of the liquid component to the liquefied gas storage tank GT. Through this, in the present invention, the gas introduced into the pretreatment unit 10 may be freed from impurities, removed from NGL, and liquefied, and finally stored in the liquefied gas storage tank GT.

The gas stored in the liquefied gas storage tank (GT) is a final product, and can be shipped, transported and sold by being unloaded on land or unloaded by LNG carriers.

The flash gas separated from the flash drum 36 is a gas containing nitrogen, methane, or the like, and includes calories. The fuel gas is supplied from the fuel supply unit 70 through a gas fuel supply line L31 connected to the flash drum 36. Can be used. In this case, the gas stored in the liquefied gas storage tank GT may be mixed with the flash gas flowing along the gas fuel supply line L31 and transferred to the fuel supply unit 70.

The condensate processing part 40 processes the condensate contained in gas. The condensate is received through the condensate collection line (L40) the impurities previously separated from the pre-washing unit 14, the knockout drum 16 of the pretreatment unit 10, the gas-liquid separator 32 of the liquefaction unit 30, etc. Afterwards, the surge vessel 42 may be used to separate the slab and the condensate.

The condensate processing unit 40 includes a heater 41, a surge vessel 42, a stabilizer 43, a phase separator 44, first to third drums 45a, 45b, and 45c, a compressor 46, and an intercooler ( 47).

The heater 41 heats the impurities. The impurity introduced into the condensate collection line L40 may be a liquid phase. In this case, the heater 41 may vaporize non-condensate hydrocarbons from the impurity through heating. Hydrocarbons vaporized from the impurities may be separated from the surge vessel 42 and transferred to the pretreatment unit 10.

The surge vessel 42 separates impurities into slabs and condensates. The surge vessel 42 may separate the condensate from impurities using a density difference, and the like, and the slop may be transferred to the slop processing unit 50.

In addition, the impurities flowing into the surge vessel 42 may include hydrocarbons vaporized by the heater 41, and the vaporized hydrocarbons may be supplied to the liquefied gas storage tank GT or the fuel supply unit 70. In addition, the gas return line L41 may be returned to the pretreatment unit 10 (eg, the gas-liquid separator 12 upstream of the mercury remover 13) to be processed.

The condensate separated from the surge vessel 42 is classified through the stabilizer 43, the first drum 45a, and the like, and finally collected in the condensate tank CT.

The stabilizer 43 classifies the condensate using a boiling point difference or the like. At this time, the gas in the liquid state is delivered to the condensate tank CT in the stabilizer 43, and the gas in the gas state is transferred to the phase separator 44, and then a part of the gas is returned to the stabilizer 43.

The phase separator 44 separates the slab from the gaseous gas delivered from the stabilizer 43. The slab is primarily separated from the surge vessel 42, but may not be completely separated and may flow into the stabilizer 43, and the phase separator 44 may use the same or similar density as that of the surge vessel 42 to separate the slope. Can be separated secondarily. The slab separated from the phase separator 44 is joined to the slab separated from the surge vessel 42 and transferred to the slab processing unit 50.

The first drum 45a to the third drum 45c may receive gas in a gaseous state separated from the stabilizer 43 and multi-stage gas-liquid separation to filter the slab in the third order. At this time, the compressor 46 and the intercooler 47 may be provided between the first drum 45a and the second drum 45b and between the second drum 45b and the third drum 45c.

At this time, according to the function of each configuration, the first drum (45a) is a suction drum (suction drum), the second drum (45b) is an interstage drum (interstage drum), the third drum (45c) is a high pressure separator (HP separator) Or the like.

As shown in the figure, the slab is separated from the surge drum 42 and the phase separator 44 by the slab of the first drum 45a to the third drum 45c. However, unlike the drawing, the arrangement or structure of the first drum 45a or the like can be changed as many as possible.

The slop processing part 50 processes the slop contained in gas. Slop may be separated from the impurity transferred from the pretreatment unit 10 to the condensate treatment unit 40 by the surge vessel 42 or the like, and unlike condensate, the material may be referred to as sewage.

The slop processing unit 50 receives and stores and purifies the slop through the slop transmission line L42 extending from the surge vessel 42 of the condensate processing unit 40, the slop drum 51, the centrifuge 52, The floatation unit 53 and the water processor 54 are included.

The slop drum 51 receives a slop from the condensate processing part 40. At this time, the slop drum 51 may temporarily store the slop, and then transfer the slop to the dirty slop tank DS through the slop storage line L50, and the hullside through the slop supply line L54 to the dirty slop tank DS. The sewage in (HS) is also delivered as described above.

The slop drum 51 may store condensate or the like that emerges from the slop to the centrifuge 52 while temporarily storing the slop. That is, the slop drum 51 may primarily purify the slops delivered to the dirty slop tank DS.

The centrifuge 52 is discharged from the slop drum 51 and centrifuged by receiving contaminated slops in which condensate and the like remain. In this case, a slop purification line L51 may be provided from the slop drum 51 to the dirty slop tank DS via the centrifuge 52 and the floatation unit 53.

The floatation unit 53 can further purify the slop discharged from the centrifuge 52. The slop purified in the floatation unit 53 may be transferred to the dirty slop tank DS or the clean slop tank CS depending on the degree of contamination.

The water processor 54 purifies the slab stored in the dirty slop tank DS to be discharged to the sea, and delivers it to the clean slop tank CS. The water processor 54 may purify the slop using various chemical and / or physical methods.

A slop treatment line L52 may be provided between the dirty slop tank DS and the clean slop tank CS, and the water processor 54 may be provided on the slop treatment line L52.

The clean slop tank CS is discharged from the slop drum 51, the centrifuge 52, and the floatation unit 53, and discharged from the dirty slop tank DS, and purified by the water processor 54. You can save your slops. At this time, the slab stored in the clean slop tank CS has a state that does not cause environmental pollution even when discharged into the sea through the slop discharge line (L53).

The heat recovery section 60 recovers the exhaust and supplies it to the heat use destination. The heat recovery unit 60 may use exhaust of a demand destination, and the demand destination is a power generation engine or a boiler as described above.

The heat recovery unit 60 may heat the oil by using the exhaust of the consumer, and allow the heated oil to be used in the heat destination. To this end, the heat recovery unit 60 includes an oil pump 61 and an oil heater 62.

The oil pump 61 delivers the oil stored in the oil tank OT to the oil heater 62. In the oil tank OT, the oil heater 62 may be provided with an oil supply line L60, and the oil pump 61 may be disposed on the oil supply line L60.

The oil heater 62 heats oil using exhaust gas. The oil heated in the oil heater 62 may be delivered to the heat source as a high temperature oil of about 260 degrees Celsius, or as a low temperature oil along the oil branch line L61.

The oil in the oil branch line (L61) is a low temperature of about 190 degrees Celsius as a portion of the oil flowing through the oil pump (61) bypasses and joins the oil heater (62) through the oil bypass line (L62) It can be oil. In this case, a separate cooler may be added to the oil branch line L61 or the oil bypass line L62.

In other words, the heat recovery unit 60 is a hot oil heated by the oil heater 62 and a low temperature oil mixed with oil heated by the oil heater 62 and bypassed by the oil heater 62, respectively. Can supply

In this case, the low temperature oil may be used for recycling the amine in the pretreatment unit 10, and the high temperature oil may be used in the dryer 17 of the pretreatment unit 10. The high temperature oil may heat-exchange with the heat source in the heat source supplyer 18 that supplies the heat source to the dryer 17, thereby heating the heat source.

Therefore, the heat recovery unit 60 may generate a high temperature oil and a low temperature oil by using one oil heater 62, and may be a method of indirectly heating a heat source by exhaust of a demand destination.

The fuel supply unit 70 supplies gas to a demand destination. The fuel supply unit 70 may mix the gas fuel discharged from the liquefied gas storage tank GT with the flash gas separated from the liquefied unit 30 and supply it to the demand destination.

The fuel supply unit 70 includes a tank return compressor 71, a suction scrubber 72, a fuel supply compressor 73, a pressure regulating valve 74, a gas heater 75, and a startup heater 76.

The tank return compressor 71 compresses a mixture of flash gas and gas fuel. However, the tank return compressor 71 does not compress the gas fuel to the required pressure of the demand destination.

The suction scrubber 72 temporarily stores the first compressed gaseous fuel and may implement a buffer for the fuel supply compressor 73. In addition, the suction scrubber 72 has a gas-liquid separation function, and the liquid gas separated from the suction scrubber 72 is returned to the liquefied gas storage tank GT.

Therefore, the tank return compressor 71 can compress the gas fuel to a level without problem even when gas is returned from the suction scrubber 72 to the liquefied gas storage tank GT.

The fuel supply compressor 73 can be provided in multiple stages and compresses the gas fuel to the required pressure of the demand destination. In particular, when the demand destination is divided into a high pressure demand destination (HP user) and a low pressure demand destination (LP user), the fuel supply compressor 73 may compress the gas fuel according to the required pressure of the high pressure demand destination.

The pressure regulating valve 74 adjusts the pressure of the gas fuel pressurized to the required pressure of the high pressure demand destination in accordance with the required pressure of the low pressure demand destination. Gas fuel supply lines L31 and L70 are connected from the flash drum 36 and the liquefied gas storage tank GT of the liquefaction unit 30 to the demand destination, and the tank return compressor 71 is provided on the gas fuel supply line L70. A fuel supply compressor 73 or the like is provided, and the gas fuel supply line L70 is branched upstream of the demand destination and connected to the high pressure demand destination and the low pressure demand destination. In this case, the pressure control valve 74 may be disposed between the low pressure demand destinations at the branch point of the gas fuel supply line L70.

The gas heater 75 heats the gas delivered from the pretreatment unit 10. In the gas delivered to the gas heater 75, impurities such as mercury are removed by the pretreatment unit 10, but NGL such as propane and ethane may not be removed.

The gas heater 75 may be provided in the pretreatment gas supply line L71, and the pretreatment gas supply line L71 may be connected to the gas fuel supply line L70 downstream of the fuel supply compressor 73. The heated gas is thus joined downstream of the fuel supply compressor 73 in the gas fuel supply line L70.

The gas heater 75 may heat the gas using the hot oil or the low temperature oil generated by the heat recovery unit 60. Of course, the gas heater 75 may heat the gas using sea water or the like.

The startup heater 76 receives and heats the gas delivered from the pretreatment unit 10 to the NGL processing unit 20 and / or the gas delivered from the gas well or the land to the pretreatment unit 10. The start-up heater 76 is provided in the start-up gas supply line L72, and the start-up gas supply line L72 is gas fuel downstream of the fuel supply compressor 73, similar to the pretreatment gas supply line L71. It may be connected to the supply line (L70). However, the start-up gas supply line L72 and the pretreatment gas supply line L71 may be independently connected to the gas fuel supply line L70, respectively.

The start-up heater 76 may heat the gas passed through the pretreatment unit 10 using electric power, unlike the gas heater 75. The start-up heater 76 is used for supplying gas fuel for initial operation of the customer. In the initial operation of the customer, the exhaust gas may not be heated by the gas heater 75 because no exhaust gas is generated to heat the oil.

Therefore, the start-up heater 76 may be provided as an electric heater 41 type that can heat the gas by using electric power that can be supplied from an emergency generator or a battery even before operation of the customer.

The flare part 80 burns gas. The flare unit 80 delivers the combustion target gas to the flare tower FT, and the combustion target gas is discharged to the outside by various factors in the process of the gas delivered from the land being processed by the gas treatment system 1. It means gas which should be discarded.

The gas to be burned may vary in humidity, temperature, and pressure depending on which of the gas flow paths it is emitted from. Therefore, the flare unit 80 may provide a flare gas supply line L80 for collecting the combustion target gas in various stages.

For example, the flare unit 80 according to the present embodiment receives the gas to be divided into a high pressure hot gas gas, a high temperature and high humidity gas gas, a high temperature and high humidity liquid gas, a low temperature dry gas gas, and a low temperature dry liquid gas to receive the flared drum 81. Can be stored temporarily.

The flare drum 81 may receive the combustion target gas and temporarily store the combustion target gas, and deliver the combustion target gas to the flare tower FT through the flare tip delivery line L81 to be combusted.

In this case, when a humid or low temperature gas is received in the flare drum 81, a drum heater 81a may be provided to heat the combustion target gas therein.

In addition, the flare unit 80 further includes a separation drum 82. The separation drum 82 receives and stores the low temperature dry gas and delivers the same to the flared drum 81 to which the low temperature dry liquid gas is supplied.

The flared drum 81 into which the high pressure hot gas gas, the high temperature and high humidity gas, or the high temperature and high humidity liquid gas flows may receive the high humidity gas, separate the gas in the liquid state, and transmit the high pressure gas gas to the slop tanks DS and CS.

On the other hand, the flared drum 81 into which the low temperature dry gas gas and the low temperature dry liquid gas flow may transfer the gas in the liquid state to the drain drum DD as waste.

The liquid gas separated from the high temperature and high humidity gas may be reused through water treatment since water is the main component, whereas the liquid gas separated from the low temperature dry gas may correspond to waste. Therefore, the liquid gas separated from the combustion target gas as described above may be treated differently.

As described above, the present embodiment can produce liquefied gas by pretreatment, NGL separation, and liquefaction of gas supplied from the land, and can efficiently implement condensate or slab treatment and fuel supply.

12 to 19 are partial conceptual views of a gas treatment system according to another embodiment of the present invention.

12 to 19, the gas treatment system 1 according to another embodiment of the present invention delivers gas purified primarily on land as the oceanic structure OP of the present invention is moored offshore. In consideration of the fact that it can be received, some configurations compared to the embodiment was improved.

Hereinafter, the present embodiment will be described based on the point that the present embodiment is different from the previous embodiment, and the descriptions omitted will be replaced with the above contents.

Instead of using hot oil in the process of drying the gas, the pretreatment unit 10 uses a heat source heated directly from the exhaust of the consumer. To this end, the heat recovery unit 60 is configured to generate only the low temperature oil using the oil heater 62 and not generate the high temperature oil independently of the low temperature oil.

In the previous embodiment, since the arrangement must produce hot and cold oils with different temperatures, it is difficult to control the amount of oil bypassing the oil heater 62, which makes the temperature control complicated and also adds a cooler. Therefore, there is a problem that CAPEX increases.

However, in this embodiment, only the low temperature oil is generated using the arrangement, and the generation of the high temperature oil is omitted, but the heat source used in the dryer 17 can be directly heated by the exhaust. To this end, the heat recovery unit 60 includes a heat source heater 63 for directly heating a heat source with exhaust, and the heat source heater 63 and the oil heater 62 are provided in series and / or in parallel with respect to the flow of the exhaust. Can be. In this case, the heat source heated in the heat source heater 63 may be higher than the oil heated in the oil heater 62.

That is, the heat recovery unit 60 directly heats the heat source used in the dryer 17 to exhaust gas of the consumer instead of the hot oil, thereby integrating the oil heated by the exhaust of the consumer into cold oil without dividing it into hot oil and cold oil. Can be. Therefore, this embodiment can reduce both CAPEX and OPEX and simplify the system to increase system operation efficiency.

The NGL processing unit 20 separates the NGL using only the gas-liquid separator 21 and one stabilizer 25. The offshore structure OP of the present invention may receive a gas already processed on land, and may further use a land installation GP provided on land.

Therefore, the amount of NGL or condensate is greatly reduced compared to the deep sea offshore structure (OP), so that the separation of NGL and the like can be made compact. All of the third column 25c and the like can be omitted.

The NGL processing unit 20 is a gas-liquid separator 21 for separating the NGL first by gas-liquid separation of the gas delivered from the pretreatment unit 10, and a stabilizer 25 for separating the NGL secondary from the gas passed through the expander 22. It may include.

At this time, in the present embodiment, only the stabilizer 25 may be provided between the expander 22 and the compressor 23 as compared with the previous embodiment in which the first column 25a is provided between the expander 22 and the compressor 23. It is apparent that the stabilizer 25 of the present embodiment can be replaced by the first column 25a of the previous embodiment.

The NGL processing unit 20 includes a drum 26, which may receive and store the NGL separated from the gas-liquid separator 21 and the stabilizer 25 through the NGL separation line L21. In the previous embodiment, ethane, propane / butane and condensate are distinguished from NGL, whereas in the present embodiment, ethane and the like are not separated separately in consideration of the fact that the amount of NGL is greatly reduced as the processed gas is processed on land. Can be stored in the drum 26 at once.

At this time, the liquid gas stored in the drum 26 may be returned to the land and processed, but the gaseous gas evaporated in the drum 26 may include light hydrocarbon having a low boiling point, and thus may be used as a gas fuel. have.

That is, in the present embodiment, by storing the NGL in the drum 26 and unloading it on land or using it as a gas fuel, the configuration for separating the NGL and individual processing of the separated materials can be largely omitted.

The liquefaction unit 30 cools the gas by using a refrigerant. In view of the fact that the offshore structure OP of the present invention is supplied with gas at high pressure on land, the present embodiment may omit the compander 31. Can be.

That is, the liquefaction unit 30 may cool the gas using the refrigerant, but liquefy the gas without forcible pressure change (expansion or compression of the gas) in the heat exchange process with the refrigerant.

In addition, the present embodiment may also omit the gas-liquid separator 32 provided between the compander 31, but in the heat exchange process with the refrigerant (for example between the pre-cooling and the main cooling of the liquefier 33) May be via the stabilizer 25 of the NGL processing unit 20.

Therefore, the liquefaction unit 30 may allow the NGL to be separated from the gas during the heat exchange process with the refrigerant. That is, the present embodiment simplifies the configuration by omitting the gas-liquid separator 32 of the embodiment in which impurities are separated, and separating the NGL by using the stabilizer 25 and storing it in the drum 26. This is possible because the present invention is an offshore offshore structure (OP) connected to land.

In this embodiment, compared to the deep sea offshore structure (OP) or the previous embodiment, the amount of equipment required for the liquefaction unit 30, and reduces the power / cooling / electrical power required for the utility CAPEX and OPEX Can be reduced.

The condensate processing unit 40 separates the impurities separated by the pretreatment unit 10 into the slab and the condensate using a density difference, and stores the separated condensate without further separation.

In the case of the previous embodiment, a condensate separated from the surge vessel 42 is provided to separate the slab that may be included in the condensate by using the first drum 45a to the third drum 45c.

However, in the present embodiment, the condensate separated from the surge vessel 42 is condensate without further separation in consideration of the fact that the amount of condensate as well as NGL in the offshore will be significantly reduced compared to the deep sea marine structure (OP). Can be stored in the tank CT.

At this time, since the amount of condensate is not large, it is not necessary to expand the capacity of the condensate tank CT even if the slabs are not further separated from the condensate separated from the surge vessel 42.

The surge vessel 42 of the present embodiment includes a partition 42a and may separate impurities separated from the pretreatment unit 10 by using a density difference into a slop and a condensate. In this case, the surge vessel 42 may be divided into one side into which impurities are introduced based on the partition 42a and the other side through which the condensate exits.

One side of the surge vessel 42 is connected to the slab processing unit 50, the other side is connected to the condensate tank (CT). The surge vessel 42 may transfer a dense slab to the slab processing unit 50, and transfer the condensate that has crossed the partition 42a to the condensate tank CT due to its low density.

However, at this time, the surge vessel 42 adjusts the amount of delivery of the slab and the condensate (discharge amount) by using ILC (Interface Level Control) so that the slab does not cross the partition 42a. Can be kept lower than).

In the surge vessel 42 of this embodiment, impurities in the land or the liquefaction unit 30 flow into one side of the partition wall 42a. The surge vessel 42 can receive and process all of the above impurities because the present invention will basically have a small amount of impurities for offshore use.

The surge vessel 42 may lower the internal pressure through PC (Pressure Control) to evaporate hydrocarbons from impurities, and the vaporized hydrocarbons are returned to the pretreatment unit 10 through the gas return line L41. That is, the condensate treatment unit 40 of the present embodiment may use the pressure drop of the surge vessel 42 without heating, so that the available hydrocarbons may naturally evaporate.

The slab processing unit 50 processes the slab separated from the surge vessel 42. In this case, the slop treatment unit 50 may share the water treatment unit 54 for treating sewage generated in the hullside HS of the offshore structure OP to purify the slop and discharge it to the outside.

Dirty slop tank (DS), water processor (54), clean slop tank (CS) may be basically provided to treat the slop that is the sewage of the hull side (HS), in one embodiment occurs in the top side (TS) A centrifuge 52, a floatation unit 53, and the like are further provided to process the slab.

However, in the present embodiment, the generation amount of all NGL, condensate, and slab can be greatly reduced by receiving and processing gas on land while being moored offshore, so that the centrifuge 52 and the floatation unit 53, etc. You can omit all of them.

Therefore, the present embodiment can allow the top side TS to be stored in the dirty slop tank DS together with the sewage of the hull side HS without any purification treatment, and the dirty slop tank DS and the clean slop tank DS. Only the water treatment unit 54 between CS) is possible to purify and externally discharge all the slabs occurring in the offshore structure OP.

However, when the pollution generated in the top side (TS) has a high pollution, there may be a limit to the treatment with the water processor 54, the present embodiment may include a configuration for separating waste from the slab in consideration of the pollution of the slab. have.

To this end, a pollution degree sensor 55 may be provided in the slop delivery line L42, and the pollution degree sensor 55 may measure the pollution degree of the slab in ppm units. If it is determined that the pollution level of the slab exceeds the reference value (30 ppm, etc.), the slab may be transferred to the slop drum 51 instead of being transferred to the dirty slop tank DS.

In this case, the slop drum 51 may separate waste from the slop by using the same density difference or the like as the surge vessel 42, and the slop separated from the slop drum 51 may be separated into the dirty slop tank DS. The waste that is delivered and separated from the slop drum 51 is transferred to the drain drum DD along the drain line L56.

That is, the slop processing unit 50 of the present embodiment may control the flow of the slop so that the slop is transferred to the dirty slop tank DS via the slop drum 51 when the slop contamination is equal to or greater than the reference value.

This flow control of the slop bypasses the slop drum 51 in the slop delivery line (L42) and the slop bypass line (L55) connected to the dirty slop tank (DS) and / or the slop delivery line connected to the slop drum (51) It may be implemented by the slab control valve 56 provided in (L42).

In this embodiment, by incorporating the topside (TS) sewage treatment into the hullside (HS) sewage treatment configuration (water treatment unit 54), the treatment of the slab can be made very simple, such as centrifugation. The configuration can be omitted, and the energy consumed in the slab treatment can be greatly reduced.

The fuel supply unit 70 mixes the gaseous fuel discharged from the liquefied gas storage tank GT with the flash gas separated from the liquefied unit 30 and supplies it to the demand destination after compression and heating.

In particular, the fuel supply unit 70 of the present embodiment may allow the gas from which impurities are removed in the pretreatment unit 10 to be mixed before heating after compression. In the previous embodiment, since the gas heater 75 or the start-up heater 76 is not provided in the gas fuel supply line L70, the pretreated gas is heated and then mixed with the flash gas and the gas fuel and supplied to the demand destination.

Therefore, in one embodiment, the temperature of the gas fuel flowing into the demand is controlled by mixing the heated gas with the compressed flash gas, so the temperature control may be very difficult.

However, the present embodiment allows the pretreated gas to join the gas fuel supply line L70 before the gas fuel is heated, so that the temperature control for heating the gas to the demanded temperature of the demand using the gas heater 75 becomes very easy. .

To this end, the fuel supply unit 70 includes a gas fuel vessel 77 provided between the fuel supply compressor 73 and the gas heater 75, and the flash gas is disposed upstream or inside the gas fuel vessel 77. It may be mixed with the gas passed through (10).

The gas heater 75 and the start-up heater 76 may be provided in parallel, and the start-up heater 76 may heat the gas passed through the pretreatment unit 10 using an emergency generator or onshore power and supply it to a demand destination. Can be. In addition, in the present embodiment, since the production of the high temperature oil by the heat recovery unit 60 is omitted, the gas heater 75 may heat the gas using a low temperature oil or the like.

In addition, in this embodiment, the tank return compressor 71 can be omitted compared to the previous embodiment. That is, the suction scrubber 72 receives the flash gas or the gas fuel without compression, and may partially return the excess gas remaining in the liquid state to the liquefied gas storage tank GT without being delivered to the demand destination.

However, in order to match the pressure difference between the flash gas and the gas fuel, a control valve (not shown) may be provided upstream of the point where the gas fuel joins the flash gas in the gas fuel supply line L70.

As such, the fuel supply unit 70 of the present embodiment omits the tank return compressor 71 and integrates it into the fuel supply compressor 73 to optimize the compression configuration, and heats after mixing instead of heating and mixing several fuels, respectively. This enables efficient temperature control.

The flare part 80 burns the gas discharged | emitted from the gas processing system 1 to the outside. In particular, the flare unit 80 according to the present embodiment may separate the combustion target gas according to the pressure and the temperature, and transmit the gas to the flare tower FT.

Specifically, the flare unit 80 has a plurality of flared drums 81 which are classified according to the pressure and temperature of the gas. The flare unit 80 according to the present exemplary embodiment may be classified into a liquid and a gas, and may be distinguished from and receive a combustion target gas according to pressure and temperature, unlike the exemplary embodiment.

For example, the flare unit 80 may be supplied to the flared drum 81 by dividing the combustion target gas into low pressure high temperature, high pressure high temperature, low low pressure low temperature, low pressure low temperature, and high pressure high temperature.

At this time, the flare drum 81 is provided so that the high pressure and the low pressure are separated from each other in the combustion target gas and the high temperature and the low pressure are separated from each other, and the flare tip delivery line L81 from each flare drum 81 to the flare tower FT. This can be connected.

In addition, the drum heater 81a may be provided in the flared drum 81 into which the low-temperature combustion target gas flows, and the separation drum 82 of one embodiment may be omitted.

The flared drum 81 into which the hot gas flows may be separated from the liquid gas and transferred to the surge vessel 42 of the condensate treatment unit 40 through the liquid return line L82. The liquid return line L82 of the present embodiment is different from the embodiment in which the flare drum 81 is connected to the slop tanks DS and CS, which is applied to the combustion target gas because the present invention receives and processes the processed gas on land. It is considered that there is not much moisture. On the other hand, the flared drum 81 into which the low temperature gas is introduced may separate the gas in the liquid state and transfer the gas to the drain drum DD.

The flare unit 80 may directly transfer the low and low pressure low temperature gas, which is relatively the lowest pressure, directly to the flare tower FT without passing through the flare drum 81. Low and low pressure low temperature gas is discharged from the liquefied gas storage tank (GT), and impurities such as condensate or waste are not mixed. Therefore, the flare unit 80 may transfer the low low pressure low temperature gas directly to the flare tower FT to combust it.

As such, the present embodiment can simplify and optimize the system by separating the flare drum 81 or the like according to the characteristics of the gas to be burned.

As described above, the present embodiment is a coastal for receiving and processing primary processed gas from the land, and simplifies the system configuration based on the low generation of NGL and the like and the use of land equipment (GP). Standardization of offshore structures (OP) is possible.

The present invention is not limited to the above-described embodiments, and of course, a combination of the above embodiments or a combination of at least one of the above embodiments and known technologies may be included as another embodiment.

The present invention has been described above with reference to the embodiments of the present invention. However, the present invention is only an example, and is not intended to limit the present invention. Those skilled in the art will not depart from the essential technical details of the present embodiment. It will be appreciated that various combinations or modifications and applications which are not exemplified in the embodiments are possible in scope. Therefore, technical matters related to modifications and applications easily derivable from the embodiments of the present invention should be interpreted as being included in the present invention.

GP: Land Equipment JT: Jetty
OP: Offshore Structure HS: Hullside
TS: Topside FT: Flare Tower
GT: Liquefied Gas Storage Tank OT: Oil Tank
CT: Condensate Tank DD: Drain Drum
DS: Dirty Slop Tank CS: Clean Slop Tank
1: gas treatment system 10: pretreatment unit
L10: gas pretreatment line 11: heater
12: gas-liquid separator 13: mercury remover
14: prewashing period 15: amine contactor
16: knockout drum 17: dryer
18: heat source supply 20: NGL processing unit
L20: NGL Separation Gas Delivery Line L21: NGL Separation Line
L22: Ethane Collection Line L23: Flare Line
21: gas-liquid separator 22: expander
23: compressor 24: precooler
25: stabilizer 25a: first column
25b: second column 25c: third column
26: drum 30: liquefaction part
L30: Gas Liquefaction Line L31: Gas Fuel Supply Line
31: Compander 31a: Inflation
31b: compression section 32: gas-liquid separator
33: liquefier 34: refrigerant supply
35: pressure reducer 36: flash drum
40: condensate processing unit L40: condensate collection line
L41: Gas Return Line L42: Slop Delivery Line
41: heater 42: surge vessel
42a: bulkhead 43: stabilizer
44: phase separator 45a: first drum
45b: second drum 45c: third drum
46: Compressor 47: Intercooler
50: Slop processing unit L50: Slop storage line
L51: Slop Purification Line L52: Slop Treatment Line
L53: Slop Discharge Line L54: Slop Supply Line
L55: Slop bypass line L56: Drain line
51: slop drum 52: centrifuge
53: floatation unit 54: water processor
55: Pollution degree sensor 56: Slop control valve
60: heat recovery part L60: oil supply line
L61: oil branch line L62: oil bypass line
61: oil pump 62: oil heater
63: heat source heater 70: fuel supply unit
L70: gas fuel supply line L71: pretreatment gas supply line
L72: Startup gas supply line 71: Tank return compressor
72: suction scrubber 73: fuel supply compressor
74: pressure regulating valve 75: gas heater
76: start-up heater 77: gas fuel vessel
80: flare part L80: flare gas supply line
L81: Flare Tip Delivery Line L82: Liquid Return Line
L83: Drain Line 81: Flare Drum
81a: drum heater 82: separation drum

Claims (8)

It is a system that is provided in offshore structures adjacent to the coast and receives and processes gas from the land.
A pretreatment unit for removing impurities from the gas and drying the same;
An NGL processor separating the NGL from the gas from which impurities are removed;
A liquefaction unit for liquefying the gas from which the NGL is separated;
Condensate processing unit for processing the condensate contained in the gas;
A slop processing unit for processing the slops contained in the gas; And
It includes a fuel supply for supplying gas to the demand source,
The condensate processing unit,
The impurity to be separated in the pre-treatment unit by using a density difference is separated into a slab and condensate, and the separated condensate is stored without further separation. The method of claim 1, wherein the condensate processing unit,
A surge vessel that separates impurities into slabs and condensates using partition walls; And
And a condensate tank for storing the condensate separated from the surge vessel. The method of claim 2, wherein the surge vessel,
One side into which the impurity is introduced based on the partition wall is connected to the slab processing unit, and the other side is connected to the condensate tank. And transfer the condensate tank to the condensate tank. The method of claim 3, wherein the surge vessel,
And controlling the delivery amount of the slop and the condensate so that the slop does not cross the partition, thereby keeping the interface between the slop and the condensate lower than the partition. The method of claim 3, wherein the surge vessel,
In addition to impurities on one side of the partition wall, impurities from the land or the liquefaction part flow in,
A gas treatment system, characterized by evaporating hydrocarbons from impurities by lowering internal pressure. The method of claim 5, wherein the surge vessel,
And a hydrocarbon evaporated from the impurities is returned to the pretreatment unit. The method of claim 6, wherein the pretreatment unit,
A mercury remover to remove mercury from the gas;
Prewash to wash away impurities;
An amine contactor for removing an acidic substance by contacting a gas with an amine; And
It includes a dryer for drying the gas is removed from the acid,
And the surge vessel returns the evaporation gas upstream of the mercury remover. An offshore structure comprising the gas treatment system of claim 1.

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